Dole told NBC News that he likes "nearly all" of the candidates, but "we need someone with experience."

"I have determined that Jeb Bush is the most qualified. Jeb has the proven leadership skills and executive experience needed to fix the problems facing our country – from the anemic economy to America's weakened standing among world leaders," Dole further explained in a statement released by the Bush campaign.

Dole has a storied relationship with the Bush family.

He ran against Bush's father, George H.W. Bush, not once but twice, seeking the Republican nomination in 1980 and 1988. In 1996, when he finally won the nod, he ran against Bill Clinton -- the husband of likely 2016 Democratic nominee Hillary Clinton.

The 41st president, in a diary entry published in a new biography by Jon Meacham, once called Dole "a son of a bitch." Relations between the two men improved during the elder Bush's presidency.

The former WWII veteran was President George W. Bush's co-chair of the President's Commission on Care for America's Returning Wounded Warriors.

The endorsement of Dole, who has long been a fixture in Republican politics, is a stark contrast, however, to the younger generation of Republicans who have backed Sen. Marco Rubio, a candidate who has focused his entire campaign around being the next generation of Republican politics.